Climate Change, Nature

Saharan Dust is Part of the Global Climate and Ecosystem

The desert wind called Calima carries sand from the Sahara Desert across the ocean and into the atmosphere, as seen here on the Canary Islands.
The desert wind called Calima carries sand from the Sahara Desert across the ocean and into the atmosphere, as seen here on the Canary Islands. Photo: Frerk Meyer | FlickrCC.

The Sahara Desert generates more dust than any other desert in the world, and that dust impacts the globe in a number of ways. A lot of it ends up in the ocean, where it introduces nutrients that otherwise might not get there, and some of those same nutrients end up falling over land as well. The dust also blocks or reflects sunlight, which can impact the formation of clouds and hurricanes.

By exploring data collected over the last century, scientists have been able to track what kinds of impact the dust has had in the past. They found that events like El Niño, the North Atlantic Oscillation, rainfall in the Sahel region of Africa, the Sahara Low Heat, and even the Intertropical Convergence Zone, can all impact how much dust is generated, where it moves, and how quickly.

The strength of a Saharan wind called the Harmattan, which blows across the massifs of North Africa, is particularly important to the process. The various other processes and events work to change the intensity of the Harmattan, which in turn determines how the dust works out each year.

Using the data they had, the researchers figured out what was happening as far back as 1850, and then they looked to the future to try and predict how things will work out over the rest of the century. What they found is that there will be a decrease in dust generation, although they aren’t entirely sure yet what that means for the rest of the world.

On the one hand, it could have some unseen benefit for humans, but that might come at the cost of reduced nutrients in soil and ocean. Maybe more of the dust will stay in Africa and help enrich arable lands there.

It could also result in a general warming of the tropical North Atlantic, which might be more suitable for hurricanes and could have a very different impact.

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Nature, Science, United States

The Science Behind the Death Valley Super Bloom

Wildflowers filled Death Valley for about two months during the recent super bloom event. It was the best bloom in several years.
Wildflowers filled Death Valley for about two months during the recent super bloom event. It was the best bloom in several years. Photo: National Park Service.

You may have heard about the Death Valley super bloom earlier this March from the abundance of photo essays on the Internet. In case you missed it, the super bloom is a period of rapid flower growth in Death Valley, one of the hottest, driest deserts in the world, where plant life is normally sparse.

During super blooms, there are flowers everywhere. Although by mid-March many of the plants are already fading away in the lower parts of the valley the can still be found at higher elevations.

Super blooms are rare, the last one was in 2005, and they’re caused by the El Niño effect. During these periods Death Valley gets far more water than normal. All deserts get some rain, and Death Valley is no different, usually netting about around 2 inches each year. But in late 2015, huge amounts of rain fell in the valley, causing flash floods that put several roads out of commission.

Much of that water seeped into the ground, where it allowed dormant seeds to grow, resulting in massive wildflower blooms. The flowers rest in the dry soil of Death Valley for years at a time, waiting for events like these rainstorms.

Combined with the subsequent mild weather of winter, these seeds were able to sprout and quickly grow. They then produce seeds before the temperatures get to high again, allowing those seeds to lie dormant until the next heavy rain season.

Twenty species of wildflower were on display in Death Valley for about two months, including the Desert Gold, with bright yellow, daisy like flowers that, this year at least, reached waist height in some places.

It’s a pretty potent reminder that nature is generally far more varied and resourceful than we give it credit for, and even in a place like Death Valley, life finds a way.

Business, Conservation, Sustainability

Turning Sewage Water Into Something Drinkable

At Orange County’s Caspers Wilderness Park showers are currently unavailable for campers due to current drought conditions throughout the state of California.
At Orange County’s Caspers Wilderness Park showers are currently unavailable for campers due to current drought conditions throughout the state of California. Photo: Mechanoid Dolly | FlickrCC.

Dow Chemical Co. and Dupont Co., two American chemical industry giants that are 118 and 213 years old, respectively, recently announced a $130 billion merger deal that would take two years to complete. Led by activist investor Dan Loeb, hedge fund Third Point LLC suggested Dow Chemical split its specialty chemical and petrochemical businesses. As part of the deal, the merged company will split into three separate entities—focused on agriculture, specialty chemicals, and materials.

In the midst of this landmark deal, Dow is continuing to solidify its place as a leader in the industry—this time on behalf of California. As California continues to deal with one of the most severe droughts on record for the fourth year in a row, Orange County—with the help of Dow Chemical—is doubling down on its unusual strategy for drinking water.

Bloomberg recently toured the facility with Snehal Desai, Dow Chemical’s global business director of the water division. It’s the largest facility in the world that practices “toilet-to-tap” technology—a complex filtration system that transforms raw sewage into an end product that’s fresher than some bottled waters. The plant, located next to the county’s water treatment facility, pumps out 100 million gallons of drinking water daily, enough to supply almost 1 million Orange County residents. The county plans to increase the output of its groundwater replenishment system by approximately 50 percent.

“Recycled wastewater will probably be the single largest source of water for California over the next quarter century,” says executive director of the Association of California Water Agencies Tim Quinn. This goes for many other water-strapped regions of the world, including Australia, China, India, Israel, Spain, the Middle East, and sub-Saharan Africa, where they have developed recycled wastewater systems for irrigation. Many areas are beginning to convert their systems to create fresh drinking water. San Diego also recently announced plans to generate 33 percent of its water from recycled sewage by 2035.

Dow Chemical has been a dominant player in advanced materials engineering for more than 100 years, generating $57 billion revenue a year in 180 countries in the world. “If not Dow, then who?” asks Desai. “The future water supply is a big-ass problem. We’ve got growing urban populations, growing industries, and dwindling resources. Who can tackle something of this magnitude? You need patience and horsepower to come up with solutions and to scale them. You can’t do that without big-boy company money.”

Ultimately, Desai believes that the same technology could accommodate individual households. Every city in the world will have to start rethinking the foundation of its water supply. “Not every city has an ocean, not everyone has good lakes and rivers,” Desai says. “But everybody’s got sewage.”